This work makes available in a single volume all the important historical essays Edgar Zilsel (1891-1944) published during WWII on the emergence of modern science. This edition also contains one previously unpublished essay and an extended version of an essay published earlier. In these essays, Zilsel developed the now famous thesis, named after him, that science came into being when, in the late Middle Ages, the social barriers between the intellectuals and the artisans were eroded, due to the fact that the rapidly expanding commercial classes of that period had a keen interest in improvements in technology. This class was city-based and stimulated a social environment in which men of learning came to regard the craftsmen and technicians with a new respect, in which they no longer felt any contempt for manual work and in which theory and practice were eventually combined to produce modern science. This critical edition also carries a long introduction in which much new material about Zilsel’s life and work is presented. It suggests that a radical new look at Zilsel’s project needs to be taken. Zilsel’s essays on the history of science look like a standard case study to substantiate a particular position on the origins of modern science, but they were also an attempt to show that lawlike explanation in history and social theory is possible. It is claimed that Zilsel’s historical essays were a part of another project he was working on which focused on the idea that social phenomena were open to causal explanation as much as physical phenomena. Hence the volume also contains the essays Zilsel wrote in relation to this other project. Previously there have been published a German and an Italian edition of the Zilsel essays. This edition is the first in English; compared to the other two editions this one is the first that includes unpublished material and the first to undertake a serious effort to research Zilsel’s life and work. What is special about this volume is the well-articulated social perspective it takes on the origins of modern science.